On 8/23/22 6:32 AM, Peter Krempa wrote:
Checkpoints created via virDomainCheckpointCreateXML are generally not
very useful as they need to be coupled with a backup.

Add a disclaimer to the docs explaining why users should use
virDomainBackupBegin instead.

Signed-off-by: Peter Krempa <pkre...@redhat.com>
---
  src/libvirt-domain-checkpoint.c | 10 ++++++++++
  1 file changed, 10 insertions(+)

diff --git a/src/libvirt-domain-checkpoint.c b/src/libvirt-domain-checkpoint.c
index de747aff01..078e999bf3 100644
--- a/src/libvirt-domain-checkpoint.c
+++ b/src/libvirt-domain-checkpoint.c
@@ -142,6 +142,16 @@ virDomainCheckpointGetConnect(virDomainCheckpointPtr 
checkpoint)
   * present, an error is thrown. This flag is incompatible with
   * VIR_DOMAIN_CHECKPOINT_CREATE_REDEFINE.
   *
+ * Note: A checkpoint represent s point in time since which blocks changed by
+ * the hypervisor are tracked.

extra space in "represent s"

Also, I think it would be more clearly understood if we changed "since" to "after".

"Note: a checkpoint represents a point in time after which blocks changed..."


This means that
+ * for a checkpoint to be generally usable for doing an incremental backup it's
+ * required to perform a backup at the same time as taking the checkpoint.

I might suggest something like:

"The main purpose of checkpoints is to enable incremental backups. But for a checkpoint to be useful for this purpose, a backup should be performed at the same time as the checkpoint is created."

+ * This is done via the virDomainBackupBegin API, which also allows to create
+ * a checkpoint at the same time. virDomainCheckpointCreateXML is generally not
+ * useful for creating checkpoints but rather only for re-creating the libvirt
+ * metadata.

my suggestion here:

"This is done via the virDomainBackupBegin API, which also allows to create a checkpoint at the same time. Creating checkpoints with virDomainCheckpointCreateXML is generally only useful for re-creating the libvirt metadata"


Reviewed-by: Jonathon Jongsma <jjong...@redhat.com>

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